A dragline is a large and expensive piece of equipment and the economic operation of one depends heavily on minimal down time. However, it occasionally happens that the operation of such a dragline is interrupted when the operator encounters certain consolidated overburden; for instance, such as frozen ground or cap rock that was unaffected during the blasting operation. To attempt digging such materials with the dragline can cause damage or excessive wear to the bucket, therefore conventional practice is to shut the dragline down and bring in smaller equipment, such as a dozer or blasting equipment. Depending on the situation, the dragline may well be out of operation for several days with obvious significant impact on the mine operating cost.
Accordingly, it is the object of this invention to provide an earth ripping device which can be attached to a conventional dragline bucket so that the dragline itself can be used to rip through and break up otherwise undiggable soils without the need to wait for auxilliary equipment.
It is a further object to provide a ripping attachment for a dragline bucket which will take fullest advantage of the dragline's tremendous power and the weight of the dragline bucket during the ripping operation.
It is a still further object to provide a ripping attachment with the aforesaid advantages which can be quickly and easily connected to the dragline bucket.
These and other objectives are achieved by the invention which comprises a ripper attachment having a base adapted to fit against the underside of the dragline bucket. At the forward end of the base is an upwardly folded lip which fits over the leading or digging edge of the bucket, and at the other end some means for connecting the attachment to the bucket hoist ropes is provided. Connected to but spaced below the base is at least one large ripping tooth with its cutting edge pointing substantially in the drag direction of the machine.
Using this device it will not be necessary to shut down the dragline when cap rock, frozen earth, or other difficult overburden is encountered. Rather, the attachment will be brought into the area of the dragline's swing radius, the operator will bring his bucket around and slip its leading edge into the lip of the attachment, and a ground worker will attach the connecting means to the bucket hoist ropes. The dragline operator will then swing the bucket with attachment over and place it onto the difficult overburden. Then as he pulls on his drag ropes, the ripper tooth will bite into the surface and will be pulled along with the full power of the machine's drag system. At the same time, the entire weight of the bucket will apply a downward force to enhance the ripper's penetration.
These and other features of the invention will be apparent and appreciated in the more detailed description which follows with reference to the accompanying drawings, which form an integral part of the specification.